SP/web2py/gluon/packages/dal/pydal/representers/__init__.py
Saturneic 064f602b1a Add.
2018-10-25 23:33:13 +08:00

268 lines
8.7 KiB
Python

from collections import defaultdict
from .._compat import PY2, with_metaclass, iteritems, to_unicode, to_bytes, \
string_types
from .._gae import gae
from ..helpers._internals import Dispatcher
from ..helpers.regex import REGEX_TYPE
representers = Dispatcher("representer")
class for_type(object):
def __init__(self, field_type, encode=False, adapt=True):
self.field_type = field_type
self.encode = encode
self.adapt = adapt
def __call__(self, f):
self.f = f
return self
class before_type(object):
def __init__(self, field_type):
self.field_type = field_type
def __call__(self, f):
self.f = f
return self
class for_instance(object):
def __init__(self, inst_type, repr_type=False):
self.inst_type = inst_type
self.repr_type = repr_type
def __call__(self, f):
self.f = f
return self
class pre(object):
_inst_count_ = 0
def __init__(self, is_breaking=None):
self.breaking = is_breaking
self._inst_count_ = pre._inst_count_
pre._inst_count_ += 1
def __call__(self, f):
self.f = f
return self
class MetaRepresenter(type):
def __new__(cls, name, bases, attrs):
new_class = type.__new__(cls, name, bases, attrs)
if bases == (object,):
return new_class
#: collect declared attributes
trepresenters = {}
irepresenters = {}
tbefore = {}
pres = {}
for key, value in list(attrs.items()):
if isinstance(value, for_type):
trepresenters[key] = value
elif isinstance(value, before_type):
tbefore[key] = value
elif isinstance(value, for_instance):
irepresenters[key] = value
elif isinstance(value, pre):
pres[key] = value
#: get super declared attributes
declared_trepresenters = {}
declared_irepresenters = {}
declared_tbefore = {}
declared_pres = {}
for base in reversed(new_class.__mro__[1:]):
if hasattr(base, '_declared_trepresenters_'):
declared_trepresenters.update(base._declared_trepresenters_)
if hasattr(base, '_declared_irepresenters_'):
declared_irepresenters.update(base._declared_irepresenters_)
if hasattr(base, '_declared_tbefore_'):
declared_tbefore.update(base._declared_tbefore_)
if hasattr(base, '_declared_pres_'):
declared_pres.update(base._declared_pres_)
#: set trepresenters
declared_trepresenters.update(trepresenters)
declared_irepresenters.update(irepresenters)
declared_tbefore.update(tbefore)
declared_pres.update(pres)
new_class._declared_trepresenters_ = declared_trepresenters
new_class._declared_irepresenters_ = declared_irepresenters
new_class._declared_tbefore_ = declared_tbefore
new_class._declared_pres_ = declared_pres
return new_class
class TReprMethodWrapper(object):
def __init__(self, representer, obj, extra=None):
self.representer = representer
self.obj = obj
if extra:
self.extra = extra
self.call = self._call_with_extras
else:
self.call = self._call
if self.obj.encode and PY2:
self.inner_call = self._inner_call_with_encode
else:
self.inner_call = self._inner_call
if self.obj.adapt:
self.adapt = self._adapt
else:
self.adapt = self._no_adapt
def _adapt(self, value):
return self.representer.adapt(value)
def _no_adapt(self, value):
return value
def _inner_call(self, value, **kwargs):
return self.obj.f(self.representer, value, **kwargs)
def _inner_call_with_encode(self, value, **kwargs):
if isinstance(value, unicode):
value = value.encode(self.representer.adapter.db_codec)
return self.obj.f(self.representer, value, **kwargs)
def _call_with_extras(self, value, field_type):
extras = self.extra(self.representer, field_type)
return self.inner_call(value, **extras)
def _call(self, value, field_type):
return self.inner_call(value)
def __call__(self, value, field_type):
return self.adapt(self.call(value, field_type))
class IReprMethodWrapper(object):
def __init__(self, representer, obj):
self.representer = representer
self.obj = obj
def __call__(self, value, field_type):
rv = self.obj.f(self.representer, value, field_type)
return self.obj.repr_type, rv
class PreMethodWrapper(object):
def __init__(self, representer, obj):
self.representer = representer
self.obj = obj
if self.obj.breaking is None:
self.call = self._call_autobreak
elif self.obj.breaking == True:
self.call = self._call_break
else:
self.call = self._call_nobreak
def _call_autobreak(self, value, field_type):
rv = self.obj.f(self.representer, value, field_type)
if rv is not None:
return True, rv
return False, value
def _call_break(self, value, field_type):
return self.obj.f(
self.representer, value, field_type)
def _call_nobreak(self, value, field_type):
return False, self.obj.f(self.representer, value, field_type)
def __call__(self, value, field_type):
return self.call(value, field_type)
class Representer(with_metaclass(MetaRepresenter)):
def __init__(self, adapter):
self.adapter = adapter
self.dialect = adapter.dialect
self._tbefore_registry_ = {}
for name, obj in iteritems(self._declared_tbefore_):
self._tbefore_registry_[obj.field_type] = obj.f
self.registered_t = defaultdict(lambda self=self: self._default)
for name, obj in iteritems(self._declared_trepresenters_):
if obj.field_type in self._tbefore_registry_:
self.registered_t[obj.field_type] = TReprMethodWrapper(
self, obj, self._tbefore_registry_[obj.field_type]
)
else:
self.registered_t[obj.field_type] = TReprMethodWrapper(
self, obj
)
self.registered_i = {}
for name, obj in iteritems(self._declared_irepresenters_):
self.registered_i[obj.inst_type] = IReprMethodWrapper(self, obj)
self._pre_registry_ = []
pres = []
for name, obj in iteritems(self._declared_pres_):
pres.append(obj)
pres.sort(key=lambda x: x._inst_count_)
for pre in pres:
self._pre_registry_.append(PreMethodWrapper(self, pre))
def _default(self, value, field_type):
return self.adapt(value)
def _default_instance(self, value, field_type):
return True, value
def get_representer_for_instance(self, value):
for inst, representer in iteritems(self.registered_i):
if isinstance(value, inst):
return representer
return self._default_instance
def get_representer_for_type(self, field_type):
key = REGEX_TYPE.match(field_type).group(0)
return self.registered_t[key]
def adapt(self, value):
if PY2:
if not isinstance(value, string_types):
value = str(value)
value = to_bytes(value)
try:
value.decode(self.adapter.db_codec)
except:
value = value.decode('latin1').encode(self.adapter.db_codec)
else:
value = to_unicode(value)
return self.adapter.adapt(value)
def exceptions(self, value, field_type):
return None
def represent(self, value, field_type):
pre_end = False
for pre in self._pre_registry_:
pre_end, value = pre(value, field_type)
if pre_end:
break
if pre_end:
return value
repr_type, rv = self.get_representer_for_instance(value)(
value, field_type)
if repr_type:
rv = self.get_representer_for_type(field_type)(rv, field_type)
return rv
from .base import BaseRepresenter, SQLRepresenter, NoSQLRepresenter
from .sqlite import SQLiteRepresenter, SpatialiteRepresenter
from .postgre import PostgreRepresenter
from .mysql import MySQLRepresenter
from .mssql import MSSQLRepresenter
from .mongo import MongoRepresenter
from .db2 import DB2Representer
from .informix import InformixRepresenter
from .oracle import OracleRepresenter
from .couchdb import CouchDBRepresenter
if gae is not None:
from .google import GoogleDatastoreRepresenter